I've done the first heist, and only after it did it tell me that my crew will get 25% better (but their cut will stay the same) after every job. Depending on the number of heists, it might be worth it to me to perform badly on the first few so that I end up with a well-trained but cheaper crew later on.
How many heists are there?
Best Answer
In Singleplayer, there are 6 heists
You can recruit crew for heist 1, 4, 5 and 6
Source: GTA WIKI